fix: auto-detect WAN roles — cellular vs fiber

- Detect Eyeride cellular interface by checking 192.168.10.x subnet
- Map correctly: ethernet/fiber → wan, Eyeride 5G → modem_0001
- Add carrier detection: AT&T for fiber gateways, Eyeride for cellular
- Fix sel_primary: fiber is active by default unless cellular route exists
- Fixes console showing 'on cellular' when actually on AT&T fiber

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

package/kit-busrouter/files/usr/lib/busrouter/telemetry-synology.sh

@@ -293,6 +293,76 @@ _collect_wan() {
 
 # ── Telemetry Collection ───────────────────────────────────────────────────
 
+# Detect which interface is the Eyeride cellular link.
+# The Eyeride runs on 192.168.10.x subnet; the interface with an IP in that
+# range is the cellular path. The other WAN interface is the primary/fiber uplink.
+# Returns: cellular_iface ethernet_iface
+_detect_wan_roles() {
+	# Check if WAN2 is on the Eyeride subnet
+	_wan2_ip=$(ip addr show "$WAN2_IFACE" 2>/dev/null | grep 'inet ' | awk '{print $2}' | cut -d/ -f1)
+	if echo "$_wan2_ip" | grep -q '^192\.168\.10\.'; then
+		echo "$WAN2_IFACE $WAN1_IFACE"  # WAN2 = cellular, WAN1 = ethernet
+	else
+		# Check if WAN1 is on the Eyeride subnet
+		_wan1_ip=$(ip addr show "$WAN1_IFACE" 2>/dev/null | grep 'inet ' | awk '{print $2}' | cut -d/ -f1)
+		if echo "$_wan1_ip" | grep -q '^192\.168\.10\.'; then
+			echo "$WAN1_IFACE $WAN2_IFACE"  # WAN1 = cellular, WAN2 = ethernet
+		else
+			# Default: WAN2 is cellular (Eyeride typically on secondary port)
+			echo "$WAN2_IFACE $WAN1_IFACE"
+		fi
+	fi
+}
+
+# Derive carrier name for an interface. Uses reverse DNS on gateway or ISP detection.
+# For the Eyeride (192.168.10.x), the carrier comes from the Eyeride's cellular operator.
+_detect_carrier() {
+	_iface="$1"
+	_gw=$(ip route show default 2>/dev/null | grep "$_iface" | awk '{print $3}' | head -1)
+	# Check if this is the Eyeride network
+	_ip=$(ip addr show "$_iface" 2>/dev/null | grep 'inet ' | awk '{print $2}' | cut -d/ -f1)
+	if echo "$_ip" | grep -q '^192\.168\.10\.'; then
+		# This is the Eyeride — carrier comes from the Eyeride's cellular operator
+		_sig=$(_eyeride_signal 2>/dev/null)
+		_sig_carrier=$(echo "$_sig" | awk '{print $5}')
+		if [ -n "$_sig_carrier" ] && [ "$_sig_carrier" != "null" ] && [ "$_sig_carrier" != "Eyeride" ]; then
+			echo "$_sig_carrier"; return
+		fi
+		echo "Eyeride"; return
+	fi
+	# For the primary/ethernet interface, try to detect from gateway
+	if [ -n "$_gw" ]; then
+		# Common AT&T gateways
+		if echo "$_gw" | grep -qE '^192\.168\.[01]\.'; then
+			echo "AT&T"; return
+		fi
+		# Common Spectrum/Charter
+		if echo "$_gw" | grep -qE '^192\.168\.[0-9]+\.'; then
+			_rev=$(nslookup "$_gw" 2>/dev/null | grep -i name | head -1 | sed 's/.*= //')
+			if echo "$_rev" | grep -qi 'att\|sbcglobal\|bellsouth'; then
+				echo "AT&T"; return
+			fi
+		fi
+	fi
+	# Fallback
+	echo ""
+}
+
+# Add carrier and identity fields to a WAN JSON object.
+# Usage: _add_wan_identity <wan_json> <iface>
+_add_wan_identity() {
+	_json="$1" _iface="$2"
+	_carrier=$(_detect_carrier "$_iface")
+	_esc_carrier=$(_json_str "${_carrier}")
+	# Strip closing brace, add carrier, re-close
+	printf '%s' "$_json" | sed 's/}$//'
+	if [ -n "$_carrier" ]; then
+		printf ',"carrier":"%s"}' "${_esc_carrier}"
+	else
+		printf '}'
+	fi
+}
+
 # Build the full telemetry JSON payload (canonical GL format).
 # Emits JSON to stdout; never fails — uses defaults for missing fields.
 telemetry_collect() {
@@ -309,42 +379,69 @@ telemetry_collect() {
 		gps_fix=$(echo "$gps_out" | awk '{print $3}')
 	fi
 
-	# WAN1 (primary uplink, typically Ethernet → modem_0001 in canonical format)
-	wan1_json=$(_collect_wan "$WAN1_IFACE")
+	# Auto-detect which interface is cellular vs ethernet/fiber
+	_cell_iface="" _eth_iface=""
+	if _roles=$(_detect_wan_roles 2>/dev/null); then
+		_cell_iface=$(echo "$_roles" | awk '{print $1}')
+		_eth_iface=$(echo "$_roles" | awk '{print $2}')
+	else
+		_cell_iface="$WAN2_IFACE"
+		_eth_iface="$WAN1_IFACE"
+	fi
 
-	# WAN2 (Eyeride cellular → wan in canonical format)
-	wan2_json=$(_collect_wan "$WAN2_IFACE")
+	# Collect metrics for both WANs
+	_eth_json=$(_collect_wan "$_eth_iface")
+	_cell_json=$(_collect_wan "$_cell_iface")
 
-	# Eyeride cellular signal for WAN2 (try to enrich with rsrp/rsrq/sinr)
+	# Add carrier identity to each WAN
+	_eth_json=$(_add_wan_identity "$_eth_json" "$_eth_iface")
+	_cell_json=$(_add_wan_identity "$_cell_json" "$_cell_iface")
+
+	# Eyeride cellular signal for the cellular interface
 	eyeride_sig=$(_eyeride_signal 2>/dev/null)
 	_rsrp=$(echo "$eyeride_sig" | awk '{print $1}')
 	_rsrq=$(echo "$eyeride_sig" | awk '{print $2}')
 	_sinr=$(echo "$eyeride_sig" | awk '{print $3}')
 	_tech=$(echo "$eyeride_sig" | awk '{print $4}')
-	_carrier=$(echo "$eyeride_sig" | awk '{print $5}')
-
-	# Build WAN2 JSON with cellular signal if available
+	# Add cellular signal fields to the cellular WAN JSON
+	if echo "$_cell_json" | grep -q '"loss_pct"'; then
+		_cell_json=$(printf '%s' "$_cell_json" | sed 's/}$//')
 		if [ "$_rsrp" != "null" ] && [ -n "$_rsrp" ]; then
-		# Replace closing brace with signal fields
-		wan2_json=$(printf '%s' "$wan2_json" | sed 's/}$//')
 			_esc_tech=$(_json_str "${_tech:-unknown}")
-		_esc_carrier=$(_json_str "${_carrier:-Eyeride}")
-		wan2_json="${wan2_json},\"rsrp_dbm\":${_rsrp},\"rsrq_db\":${_rsrq},\"sinr_db\":${_sinr},\"technology\":\"${_esc_tech}\",\"carrier\":\"${_esc_carrier}\"}"
+			_cell_json="${_cell_json},\"rsrp_dbm\":${_rsrp},\"rsrq_db\":${_rsrq},\"sinr_db\":${_sinr},\"technology\":\"${_esc_tech}\"}"
+		else
+			_cell_json="${_cell_json}}"
+		fi
+	fi
+
+	# WAN mapping in canonical GL format:
+	#   modem_0001 = cellular (Eyeride 5G)
+	#   wan        = ethernet/fiber (AT&T Uverse)
+	_wan_modem="$WAN2_IFACE"  # which physical iface maps to modem_0001
+	_wan_ether="$WAN1_IFACE"  # which physical iface maps to wan
+
+	# Check if roles were swapped by auto-detection
+	if [ "$_cell_iface" != "$WAN2_IFACE" ]; then
+		# WAN1 is cellular, WAN2 is ethernet
+		_modem_json="$_cell_json"
+		_ether_json="$_eth_json"
+	else
+		# WAN2 is cellular, WAN1 is ethernet (normal)
+		_modem_json="$_cell_json"
+		_ether_json="$_eth_json"
 	fi
 
 	# Active WAN: determine from routing table (default route interface)
-	sel_primary="modem_0001"
+	sel_primary="wan"  # default: fiber/ethernet is primary
 	default_iface=$(ip route show default 2>/dev/null | awk '{print $5}' | head -1)
-	if [ "$default_iface" = "$WAN2_IFACE" ]; then
-		sel_primary="wan"
+	if [ "$default_iface" = "$_cell_iface" ]; then
+		sel_primary="modem_0001"  # cellular is the active path
 	fi
 
 	# Starlink — detect if present
 	sl_lat="null" sl_dl="null" sl_obs="0" sl_outage="0"
-	# Starlink is typically on a USB ethernet adapter or separate VLAN
 	if ip link show 2>/dev/null | grep -qi starlink; then
-		# Basic Starlink check — if interface exists, try to get metrics
-		sl_iface=$(ip link show 2>/dev/null | grep -i starlink | head -1 | awk -F': ' '{print $2}' | awk '{print $1}')
+		sl_iface=$(ip link show 2>/dev/null | grep -i starlink | head -1 | awk -F": " '{print $2}' | awk '{print $1}')
 		if [ -n "$sl_iface" ]; then
 			sl_ping=$(_ping_iface "$sl_iface")
 			sl_lat=$(echo "$sl_ping" | awk '{print $1}')
@@ -362,7 +459,7 @@ telemetry_collect() {
 	printf '{"device_id":"%s","timestamp":%d,"uptime":%d,"version":"%s","platform":"synology","sel_primary":"%s","active_wan":"%s","gps":{"lat":%s,"lon":%s,"fix":%s},"wan":{"modem_0001":%s,"wan":%s},"sim_slot":null,"starlink":{"latency_ms":%s,"dl_bps":%s,"obstructed":%s,"outage":%s},"state":%s}\n' \
 		"${esc_id}" "${now:-0}" "${uptime_s:-0}" "${esc_ver}" "${esc_sel}" "${esc_sel}" \
 		"${gps_lat}" "${gps_lon}" "${gps_fix}" \
-		"${wan1_json}" "${wan2_json}" \
+		"${_modem_json}" "${_ether_json}" \
 		"${sl_lat}" "${sl_dl}" "${sl_obs}" "${sl_outage}" \
 		"${state}"
 }